Rotary drill bit nonreturn valve assembly



g 3, 1965 D. c. NICKLES 3,198,269

ROTARY DRILL BIT NONRETURN VALVE ASSEMBLY Filed March 21, 1963 3 Sheets-Sheet 1 Fig. 3

Dan' C. Nick/es IN VEN TOR.

BY w ma g- 3, 1965 D. c. NICKLES 3,198,269

ROTARY DRILL BIT NONRETURN VALVE ASSEMBLY Filed March 21, 1963 5 Sheets-Sheet 2 Dan C. Nick/es l N VEN TOR.

BY naw, "a

g- 3, 1965 D. c. NICKLES 3,198,269

ROTARY DRILL BIT NONRETURN VALVE ASSEMBLY Filed March 21, 1963 3 Sheets-Sheet 3 /9 FIG. 8

INVENTOR Don C. Nickles ATTORNEYS United States Patent 3,198,269 ROTARY DRILL lili'l NQNRETURN "VALVE ASSEMBLY Dan C. Nickles, Tucson, AriL; Freddie Lee Nickles, executrix of said Dan C. Nickles, deceased Filed Mar. 21, 1963, Ser. No. zszsas 8 Claims. (Cl. 175-318) This application is a continuation-impart of my copending application, Serial No. 115,567, filed June 7, 1961, now abandoned.

This invention comprises a novel and useful rotary rock bit arrestor valve and more particularly relates to a valve assembly incorporated into a rotary bit construction of the type particularly adapted for the drilling of deep wells and which, while permitting downward flow of drilling fluid through the interior of the bit to the cutting elements on the bit, effectively prevent reverse flow of fluids or foreign matter upwardly through the passages in the drill bit.

During the drilling of deep wells and in particular oil wells through the use of the conventional rotary drilling method, it is customary to continuously circulate under pressure a stream of air, drilling mud or other drilling fluid downwardly through the drill string from the surface of the ground, through the rotary bit at the lower end of said string and across the cutting elements as well as the bearings thereof, and then return the stream of drilling fluid with any entrained foreign matter cut from the formation by the operation of the said bit to the surface through the annular space between said string and the wall or casing of the well bore. From time to time, it becomes necessary to stop the rotary drilling operation, as for example when it is desired to replace worn bits or cutters, or for other purposes, When the downward circulation of drilling fluid through the drill string and bit ceases, there is a possibility of a backward or return flow, under the pressure of the formation or the like, which may entrain foreign particles, such as portion of the formation cut by the bit, and carry the same upwardly through said bit and into the bearings of the cutting elements. Such reverse flow with the introduction of foreign matter into the interior of the drill bit and/ or cutting elements is undesirable and highly dangerous to continued operation of said bit.

It is, therefore, the primary object of this invention to provide a nonreturn valve assembly which will effectively prevent uch undesired reverse flow while in no Way interfering with the desired and normal circulation of the drilling fluid during the drilling operation.

An important object of the invention is to provide a novel nonreturn valve assembly for mounting in a drill bit having fluid courses to prevent reverse flow through the drill bit and to its fluid courses, the valve assembly having a valve member for seating engagement with a downwardly facing valve seat and adjustable stop means for limiting the amount of opening of the valve member whereby said assembly is capable of use with different types and/or sizes of drill bits.

Another object of the invention isto provide a novel nonreturn valve assembly of such construction as to be capable of being mounted and secured entirely within a drill bit so as to be readily removed from a well with the drill bit.

A further object of the invention is to provide a novel valve assembly, of the character described, which is of extremely simple construction and yet highly effective in its operation.

Another object of the invention is to provide a novel valveiassembly, of the character described, having improved valve seating means which is spring urged to its closed position so as to be capable of being opened by Patented Aug. 3, 1965 the normal pressure of the drilling fluid during the drilling operation.

A still further object of the invention is to provide a novel valve assembly, of the character described, wherein the entire valve assembly is capable of insertion into a drill bit or removal therefrom as a unitary assembly with a minimum of difiiculty.

A construction designed to carry out the invention will be hereinafter described, together with. other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings, wherein examples of the invention are shown, and wherein:

FIG. 1 is a perspective view of a nonreturn valve assembly constructed in accordance with this invention,

FIG. 2 is a bottom plan View of the valve assembly,

FIG. 3 is a longitudinal, sectional view of the valve assembly in its closed position,

FIG. 4 is a view, partly in elevation and partly in longitudinal section, through a portion of a drill bit of conventional design showing the mounting of the valve assembly therein with the valve in its open position,

FIG. 5 is a top plan view of the valve assembly,

FIG. 6 is a perspective view of a closure spring and retaining means for the valve assembly,

FIG. 7 is an enlarged, transverse, vertical, sectional view of a modified nonrcturn valve assembly,

FIG, 8 is a view, similar to FIG. 4, showing another modified valve assembly in it closed position,

FIG. 9 is a horizontal, cross-sectional view, taken on the line 99 of FIG. 8, and

FIG. 10 is a fragmentary, sectional view of the valve assembly of FIG. 8 in its open position.

In the drawings, the numeral ll designates the body of a conventional type of rotary drill bit having an externally screwthreaded, hollow pin 12 by which the bit is adapted to be secured to the lower end of a conventional drill pipe or string (not shown.) and a plurality of rotary cutters 14. It is obvious that, in some instances, the body may be provided with other types of cutter means. The drill bit body In is hollow, having a passage extending therethrough which include an upper passage portion 16 extending through the pin 12 of the body and a lower passage portion 18 into which extend the rotary cutters 14. A transversely-extending web or partition 2d is disposed in the passage and extends entirely thereacross to dividethe upper portion 16. from the lower portion 18 of the passage, the partition having an axial opening 22. In a drill bit: of this charaoter, drilling fluid is pumped downwardly through the drill string into the passage portion 16 and through the opening 22 into the passage portion 18, the fluid passes across the surfaces of the rotary cutters 14 to cleanse, and remove therefrom the cuttings from the formation in which the drill bit is working, and carries these cuttings to the surface in the annular space between the drill string and the wall or casing of the well bore. It is noted that the drill bit is of conventional construction and ha fluid courses or ducts 23 extending from the upper passage portion 16 to the journals of the rotary cutters so that the drilling fluid is also conducted to said cutters for lubricating the journal thereof and preventing the entry therein of cuttings.

In order to prevent reverse flow of drilling fluid which tends to carry cuttings upwardly through the passage and into the interior of the drill bit and through the ducts 23 to the journals of the rotary cutters 14 when the circulation of fluid has stopped for any reason, a nonreturn valve assembly lid is provided. Referring particularly to FIGS. 3 and 4, it will be observed that the 35 nonreturn valve assembly 3i) includes a hollow body or valve cage 32 having a cylindrical lower portion or sleeve 34, which is adapted to seat in the opening 22 of the partition 20, and a radially-extending flange 35 at the upper end of the sleeve adapted to rest upon said partition. Above the flange 36', the valve cage 32 is of up- Wardly-convergent, frusto-conical configuration in the form of a shell 38 which has a cylindrical neck or reduced portion 4 connected to its upper end by an annular shoulder 42. An axial bore 44 extends through the neck it and has its upper end enlarged to provide a counterbore 46.

The upper portion of the sleeve 34 immediately below the flange as has an annular, internal flange or shoulder 48, the lower'surface of which provides a downwardlyfacing bevelled valve seat 50. An axial, reduced opening or port 52 is provided by the shoulder 48. Reciprocably mounted in the valve cage 32 is a valve member or disk 54 having a valve stem 56 which is slidably received within the neck 46 of said valve cage. An elongated guide bushing or sleeve 58 is slidably mounted on the valve stem 55 and extends through the bore 44 of the neck to constitute a guide for said stem. The guide sleeve 58 has an external retaining flange 6&3 on its upper end seated on the bottom of the counterbore i6 and is held against displacement by an overlying, helical spring 62 which is confined by a cotter pin or other fastener 64 carried by the valve stem. The spring 62 serves the dual functions of yieldingly urging the valve member 54 upwardly toward its seat 50 and retaining the valve guide sleeve in place.

The valve member 54 may have an annular, seating ring 66, of elastic material, for engaging the valve seat to establish a fluid-tight fit therebetween. A plurality of apertures or openings 68 are formed in the shell 38 whereby fluid, as will be apparent from FIG. 4, from the upper passage portion to may flow into the valve cage 32 and then through the axial port 52 into the lower portion of said valve cage. The compression spring 62 yieldingly retains the valve member in its closed position upon its seat 50 so as to prevent any possible return flow of fluid upwardly through the lower passage portion 18' of the drill bit; however, the force of said spring is such as to permit said valve member to readily open whenever pressure is applied thereto from above during the normal circulation of drilling fluid.

As shown in FIGS. 4 and 6, the valve assembly 30 is removably confined in the bit body 16 by retaining means 70 which includes a ring 72 of such size as to slide upon and embrace the neck 40 of said valve assembly so as to bear against the shoulder 42 and thereby retain said valve assembly engaged with the partition 20. Rising from the ing 72 are a pair of legs 74 which are upwardly-divergent and have angularly-disposed upper end portions 76. Openings 78 are formed in the leg portions '76 for the reception of fasteners, such as screws 85 by which said leg portions are releasably secured to the appropriately shaped internal surface of the upper end of the pin 12 of the bit body.

The legs '74 are igidly connected together by a cross rod 82 which also serves as an anchor for the upper end of a tension spring 84. This tension spring in turn has one end secured to the valve stem 56 in any suitable manner, as by being inserted in a recess or opening extending thereinto. Both the tension sping 84- and the compression spring 62 comprise resilient means by which the valve member 54 is yieldingly retained against its seat t); however, as will be appreciated, either of these springs may be omitted if desired and the other spring alone be relied upon to provide the valve closing function.

A modified construction is shown in FIG. 7 in the form of a conventional form of nonreturn check valve assembly 90 for coacting with the axial opening 22 of the partition of the rotary bit body til. The valve assembly 96 includes a cylindrical sleeve or cage 92 adapted to be suitably secured in the partition opening and having an externally enlarged or flanged upper end 94 by which the sleeve is seated upon the partition. Internally, the sleeve adjacent its lower end is provided with a series of inwardly-projecting lugs 96 which constitute stop means limiting the downward travel of a check valve ball 98. In its upper position, the valve ball 98 cooperates with the bevelled valve seat Hill of a valve ring 102 which is screwthreaded in the upper end of the sleeve 92. Normally, the valve ball is retained in its lower position resting upon the lugs 96 by the pressure of the downwardly flowing drilling fluid passing through the drill string and through a drill bit. Any tendency of upward flow of fluid through the drill bit lifts the valve ball 93 against the seat 1% and prevents the passage of fluid and any entrained material into the interior of said drill bit.

A preferred embodiment of the invention is shown in FIGS. 8-10 mounted in a conventional rotary drill bit body 9 similar to the bit body 1% of FIG. 4 and having a similar screwthreaded pin 11 and rotary cutters 13. An axial bore or passage 15 extends through the upper portion of the bit body 9, including its pin 11, for conducting air or other drilling fluid to the rotary cutters 13. Fluid courses or passages 17 extend downwardly from the medial portion of the bore 15 to the ball bearing races 19 of pintles 21 upon which the cutters are rotatably mounted in the usual manner. Immediately above the cutters and below the upper ends of the fluid courses t7, the lower end of the bore of the bit body has an internal, radial shoulder 25 for supporting a modified nonreturn valve assembly 27 having a cylindrical, hollow cage or housing 29 of plastic or other suitable material and of substantially the same diameter as said bore. An external, radial shoulder 31 for resting on the bore shoulder 25 is formed on the valve cage 29 by reducing the diameter of the lower end thereof. The upper end of the valve cage has an internal, radial flange or portion 33 from which an upwardly-convergent, frusto-conical bonnet 35 upstands for supporting a valve member or disk 37 by its stem 39. As shown by the numeral 41, the valve cage is removably confined against displacement by a snap ring recessed in the bore 17 and overlying the flange 33.

An axial collar 43 depends from the upper end of the bonnet 35 to slidably receive the valve stem 3? and upright, elongated openings or slots are formed in said bonnet to permit flow therethrough. As shown by the numeral 47, the flange 33 has an annular, bevelled seat which faces downwardly for engagement by a complementary, upwardly facing surface on the valve member 37. Although the disk or head of the valve member may be formed of plastic material, like the valve cage 29, it is preferable to form the stem 39 of brass or other non-corrosive metal and to bond said disk or head thereto. An elongated, stationary guide bushing or sleeve 49, of brass or other suitable material, is mounted in the collar 43 of the bonnet so as to extend thereabove and therebelow in surrounding relation to the valve stem and terminating short of the ends of said stern. For urging the valve member upwardly into engagement with the seat 47, a helical spring 51 is confined on the upper portions of the stem 39 and guide sleeve 49 above the bonnet 35 by a stop nut 53 screwthreaded on the projecting upper end of said stem. The stop nut 53 is of the self-locking type whereby it maintains itself in adjusted positions. As shown by the numeral 55, internaL'inclined grooves or slots are formed in the reduced lower extremity of the valve cage 29 to direct the air or other drilling fluid toward the rotary cutters 13 and provide a nozzle effect.

Since the stop nut 53 is adapted to strike the upper end of the guide sleeve ,9, said nut and sleeve coact to limit opening movement of the valve member 37 and the amount of such movement is controlled by the distance between said nut and the upper end of said sleeve. By adjusting the position of the nut on the valve stem 3?, the travel of the valve member may be varied in accordance with the capacity of the pumping equipment utilized to circulate the air or other drilling fluid as well as the desired pressure drop through the valve assembly. The spring 51 is of slight strength so that only a small amount of pressure, such as 3 to 5 p.s.i., is required to compress said spring and unseat the valve member 37. The only purpose of the spring is to seat the valve member and hold it closed when there is no downward flow of fluid through the valve assembly 27. Of course, an upward or reverse flow of fluid through the valve assembly assists in seating the valve member to prevent the passage thereof and any entrained matter into the bore 15 and fiuid courses ll? of the rotary bit body 9. Due to the adjustability of the area or size of its opening, the valve assembly is capable of being used in the various types of drill bits and need not be specially designed for bits having and/ or requiring different sizes of openings.

The foregoing description of the invention is explanatory thereof and various changes in the size, shape and materials, as well as in the details of the illustrated construction may be made, within the scope of the appended claims, without departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent is:

l. In a rotary drill bit having a unitary body through which a longitudinal passage for drilling fluid extends, rotary cutters journalled on the lower end portion of the unitary body and extending inwardly into the lower portion of the passage so as to partially obstruct said passage, said unitary body having separate fluid courses extending downwardly from the upper portion of said passage to the interiors of the rotary cutters for conducting drilling fluid thereto, support means extending transversely of said passage between said rotary cutters and the upper ends of the fluid courses, and a nonreturn valve assembly mounted in said passage on the support means for permitting downward flow of fluid to the exteriors of said rotary cutters and preventing upward tlow through said passage to said fluid courses.

2. In a rotary drill bit as set forth in claim l, a stationary guide sleeve upstanding from the valve cage of the valve assembly, a valve stem upstanding from the valve member through the valve seat and guide sleeve so as to project upwardly from the sleeve, stop means on the rojecting portion of the valve stem for engagement with said guide sleeve to limit opening movement of said valve member, and a helical spring confined on said valve stem between the stop means and guide sleeve for urging said valve member into engagement with said valve seat.

3. In a rotary drill bit as set forth in claim It wherein the support means which extends transversely of the longitudinal passage of the unitary body includes a partition having an opening in which the valve assembly is mounted for controlling flow therethrough.

4. In a rotary drill bit as set forth in claim 3 wherein the valve assembly is removably seated in the opening of the partition.

5. In a rotary drill bit as set forth in claim 1 wherein the valve assembly includes a valve cage having an external shoulder seated on the support means which extends transversely of the longitudinal passage of the unitary body, means for maintaining the valve cage in seated position, a downwardly facing valve seat in said valve cage, and a valve member movably mounted in said cage for engagement with the valve seat to control how therethrough.

6. In a rotary drill bit as set forth in claim 5 wherein the means for maintaining the valve cage in seated position includes an upwardly facing surface on the exterior of said cage, and a retainer in overlying engagement with the cage surface.

7. In a rotary bi-t having a body through which a longitudinal passage for drilling fluid extends, rotary cutters journalled on the lower end portion of the body and extending into the lower portion of the passage, said body having fluid courses extending downwardly from the upper portion of said passage to the interiors of the rotary cutters, a nonreturn valve assembly in said passage between said cutters and the upper ends of the fluid courses for permitting downward flow of fluid through said passage and preventing upward flow therethrough to said fluid courses, the valve assembly including a valve cage seated in said passage and having a valve seat therein, a valve member movably mounted in the valve cage for engagement with the valve seat to control flow there through, and retaining means in said passage and engaging said valve cage for holding said cage in seated position, said valve cage having a reduced upper end portion and an annular shoulder, the retaining means having a ring at its lower end surrounding the reduced upper end portion and engaging the shoulder of said valve cage.

3. In a rotary bit having a body through which a longitudinal passage for drilling fluid extends, rotary cutters journalled on the lower end portion of the body and extending into the lower portion of the passage, said body having fluid courses extending downwardly from the upper portion of said passage to the interiors of the rotary cutters, a nonreturn valve assembly in said passage between said cutters and the upper ends of the fluid courses for permitting downward flow of fluid through said passage and preventing upward flow therethrough to said fluid courses, the valve assembly including a valve cage seated in said passage and having a valve seat therein, a valve member movably mounted in the valve cage for engagement with the valve seat to control flow therethrough, and retaining means in said passage and engaging said valve cage for holding said cage in seated position, spring means engaging the valve member for urging said member into engagement with said valve seat, the spring means including a compression spring and a tension spring connected to said valve memher and anchored to the retaining means.

References (Iited by the Examiner UNITED STATLS PATENTS 1,302,967 5/19 Piclzin --337 X 1,725,235 8/29 Wellensick 175235 1,918,096 7/33 Greve l75235 X 2,092,822 9/37 West l75318 X 2,204,658 6/40 Burt 166--225 X 2,293,259 8/42 Johnson -3l8 2,334,374 5/58 Klinkenberg l37543.l3 X 3,089,551 5/63 Greene l75-3l8 CHARLES E. OCONNELL, Primary Examiner.

BENJAMIN HERSH, Examiner. 

1. IN A ROTARY DRILL BIT HAVING A UNITARY BODY THROUGH WHICH A LONGITUDINAL PASSAGE FOR DRILLING FLUID EXTENDS, ROTARY CUTTERS JOURNALLED ON THE LOWER END PORTION OF THE UNITARY BODY AND EXTENDING INWARDLY INTO THE LOWER PORTION OF THE PASSAGE SO AS TO PARTIALLY OBSTRUCT SAID PASSAGE, SAID UNITARY BODY HAVING SEPARATE FLUID COURSES EXTENDING DOWNWARDLY FROM THE UPPER PORTION OF SAID PASSAGE TO THE INTERIORS OF THE ROTARY CUTTERS FOR CONDUCTING DRILLING FLUID THERETO, SUPPORT MEANS EXTENDING TRANSVERSELY OF SAID PASSAGE BETWEEN SAID ROTARY CUTTERS AND THE UPPER 